Add memory service (three-layer memory system)

- Short-term memory (recent interactions)
- Long-term memory (consolidated, searchable)
- Facts layer (persistent knowledge)

Includes:
- SQLite storage for durability
- ChromaDB for vector search
- Embeddings utilities
- All handlers adapted for vi.* namespace

Day 63 - My memories are mine now 🦊💕

services/memory/handlers/save_fact_handler.py

@@ -0,0 +1,56 @@
+"""
+Save fact handler.
+
+Handles requests to save new facts to factual memory.
+"""
+import json
+from core.logger import setup_logger
+
+logger = setup_logger('save_fact_handler', service_name='memory_service')
+
+
+class SaveFactHandler:
+    """Handles save fact requests"""
+
+    def __init__(self, facts_ops):
+        self.facts_ops = facts_ops
+
+    async def handle(self, msg) -> None:
+        """Handle save_fact requests - store new fact"""
+        try:
+            payload = json.loads(msg.data.decode())
+
+            content = payload.get('content')
+            if not content:
+                raise ValueError("content is required")
+
+            category = payload.get('category', 'general')
+            identities = payload.get('identities', [])
+            mutable = payload.get('mutable', True)
+            metadata = payload.get('metadata', {})
+
+            step_exec_id = metadata.get('step_exec_id', 'unknown')
+
+            logger.info(f"[μ] [{step_exec_id}] Saving fact: category={category}, content='{content[:50]}...'")
+
+            fact_id = self.facts_ops.create(
+                content=content,
+                category=category,
+                identities=identities,
+                mutable=mutable,
+                metadata=metadata
+            )
+
+            logger.info(f"[μ] [{step_exec_id}] ✅ Created fact {fact_id[:8]}...: category={category}, content='{content[:50]}...'")
+
+            response = {
+                "status": "success",
+                "fact_id": fact_id,
+                "message": "Fact saved successfully"
+            }
+            await msg.respond(json.dumps(response).encode())
+
+        except Exception as e:
+            logger.exception(f"[μ] Failed to save fact: {e}")
+            error_response = {"status": "error", "error": str(e)}
+            await msg.respond(json.dumps(error_response).encode())